Growth and Investigation of Nd1-xSmxScO3 and Sm1-xGdxScO3 Solid-Solution Single Crystals

R. Uecker a, D. Klimm a, R. Bertram a, M. Bernhagen a, I. Schulze-Jonack a, M. Brützam a, A. Kwasniewski a, Th.M. Gesing b and D.G. Schlom c, d a Leibniz Institute for Crystal Growth, Max-Born-Str. 2, D-12489 Berlin, Germany b Solid State Chemical Crystallography, Institute for Inorganic Chemistry, University Bremen, Leobener Str./NW2, D-28359 Bremen, Germany c Department of Materials Science and Engineering, 230 Bard Hall, Cornell University, Ithaca, New York 14853-1501, USA d Kavli Institute at Cornell for Nanoscale Science, Ithaca, New York, 14853, USA

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The pseudo-cubic lattice parameters of rare-earth (RE) scandate, REScO3, single crystals grown by the Czochralski technique with RE = Dy to Pr lie between about 3.95 and 4.02 Å. These crystals are the only available perovskite substrates in this lattice constant range that can withstand virtually any thin film growth conditions. Two members of this series, PmScO3 and EuScO3, are, however, not suitable for substrate applications. Because the pseudo-cubic lattice parameters between neighbouring REScO3 compounds decrease with rising atomic number of the RE in about 0.01 Å steps, the unsuitability of PmScO3 (radioactivity) and EuScO3 (incompatibility with Si) causes an interruption in this lattice spacing sequence. To replace them, solid solutions of their adjacent rare-earth scandates, i.e., (Nd0.5Sm0.5)ScO3 and (Sm0.5Gd0.5)ScO3, were grown by the Czochralski method. Their average pseudo-cubic lattice parameters of 3.9979 Å and 3.9784 Å are very close to those of PmScO3 and EuScO3, respectively, and they show very low segregation. These qualities make these solid solutions excellent substitutes for PmScO3 and EuScO3.

DOI: 10.12693/APhysPolA.124.295 PACS numbers: 64.75.Nx, 81.10.Fq, 81.30.-t